Author Topic: Taking a hard look at converting my 86 350 carb to TBI, got some questions  (Read 15932 times)

Offline lbrowne

  • Newbie
  • Posts: 65
I have access to a huge scrapyard that I'll be able to pull alot of parts from. I kind of need to know what trucks I can work with. (what range year, vans trucks etc)

I have to pull the heads to change them over to the rebuilt ones I got, so I'm trying to figure out what to do while I got her apart. I would really like the ol girl to be fuel injected if I can do it on the cheap.

Things I know I need to get:

intake manifold with TBI
fuel pump (for a fuel injected truck)
02 sensor
knock sensor
ECU from fuel injected truck
coolant temp sensor
vehicle speed sensor

What things are mandatory? (do I need a later year instrument cluster?)
What range of vehicles do I have to work with?
Outside of the O2 sensor and intake manifold, is there a quick reference for the location of the other sensors?

I'll print the answers and bring it to the scrapyard with me.

How to's or write ups where people took their lumps on this install would help. I found some articles in the archives, but nothing with good photos.

Much appreciated fellas.

1986 GMC Sierra Classic
My first truck! (completely stock...for now)

Offline topp

  • Frequent Member
  • **
  • Posts: 498
Fuel Tank FOR an injected truck...
ESC module
Fuelie Distributor with Fuelie ICM
Heads for the manifold (different pattern of bolts).
Oil Pressure cut off switch.
Fuel pump harness and relay

Just a few things I know I have on my TBI that you didn't list
'90 Suburban TBI 350

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19186
You'll want the whole fuel tank sending unit not just the pump. I just converted one of mine to tbi.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline lbrowne

  • Newbie
  • Posts: 65
So I need the whole tank and not just the sending unit and pump? I can't reuse my existing tanks?

So the rebuilt heads I bought won't work with a TBI intake manifold. I guess this throws this idea out the window! lol

Can I take all these things off an 88-94 chevy/gmc truck/van?
1986 GMC Sierra Classic
My first truck! (completely stock...for now)

Offline topp

  • Frequent Member
  • **
  • Posts: 498
So I need the whole tank and not just the sending unit and pump? I can't reuse my existing tanks?

So the rebuilt heads I bought won't work with a TBI intake manifold. I guess this throws this idea out the window! lol

Can I take all these things off an 88-94 chevy/gmc truck/van?

The Fuel injected tanks have baffles where as the carb tanks don't....

There are "adapters" for the manifold bolts, for non tbi manifolds on TBI heads....Not sure of the other way around...

'90 Suburban TBI 350

Offline FritzA

  • Newbie
  • Posts: 16
You can use a regular 4 barrell manifold with your pre-tbi heads. Summit and Jegs sell adapters to bolt a TBI to those manifolds.

Offline Stewart G Griffin

  • Senior Member
  • ****
  • Posts: 3324
With all this recent talk about converting to TBI (see the other firebird post also), has anyone considered or done a conversion with holley's pro-jection tbi system?

i know i said i would be sticking with carbs, but the more i examine their system, the more intrigued i am about it.  And, at about 1K, it would pay for itself quicker than maybe expected.

It comes complete including fuel pump and all new components;  Don't need to scrounge/chase down parts---this in and of itself, costs money and time.

With complete detailed instructions, it looks like it could be installed in about a weekend.  They have the instructions viewable online.   They also have diagnosing and troubleshooting section.

2) You asked about how to/writeup links:
http://67-72chevytrucks.com/vboard/showthread.php?t=352321

Took him over 4 months to install gm TBI system.  

To me it seems like the Holley system is the easiest, cheapest way to go TBI.
« Last Edit: May 31, 2010, 08:10:56 am by Stewart G Griffin »

Offline lbrowne

  • Newbie
  • Posts: 65
You know, I was just looking at the kit that Holley has coming soon - the Avenger EFI kit for TBI setup. The 550-400 looks to be what I would go after.

I wonder what the pricing is going to be like when it comes out.
1986 GMC Sierra Classic
My first truck! (completely stock...for now)

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19186
You can use any 73-87 style tank with a tbi or tpi, you just need the sender and the pump.

Aftermarket TBI or TPI systems are a waste of $ when you can easily modify and retrofit a factory system which you can get for $200 bucks or less. If you're loaded or have money to burn go for it but to me $2000+ or $200 bucks well do the math.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Stewart G Griffin

  • Senior Member
  • ****
  • Posts: 3324
1) the new holley system is probably better, but 1 grand more over the older system.  

2) On paper using the GM system may be cheaper but:
a) Chasing down parts (as we all well know) takes time, which=money and money, which=money+time.

b) For GM TBI, If the stock tank can be used, does the pump need to be put in the tank or can we use any elec. pump?

c) You get all new parts with holley or aftermarket probably with a guarantee.   Salvage yd parts-----???

d) Realistically, is the GM TBI system going to be straightfoward to install?   Does anyone supply a kit---with instructions?
i'm pretty sure even i could install the holley system in a weekend.  GMTBI could take months if not longer.  Again, the time/money issue.

So for someone like me, an aftermarket system might be "cheaper."
« Last Edit: May 31, 2010, 08:12:12 am by Stewart G Griffin »